What is Cancer?
Cancer is a disease that develops when cells in the body become abnormal and start growing out of control. These abnormal cells can grow into tumors, which may invade nearby tissues and spread to other parts of the body. This process is called metastasis.
Cancer can be any type of cell in the body, including skin cells, bone cells, blood cells, or cells that line the digestive tract and reproductive organs. Normally, cells grow and divide to produce more cells as the body needs them. Old or damaged cells die and new cells replace them. This process is regulated by proteins that control cell growth and division, known as oncogenes and tumour suppressor genes. Cancers occur when some of these genes get changed, or mutate, and no longer control cell growth.
These changes, or mutations, usually occur in parts of DNA that code for proteins. Most of the time, cancer-causing genes are turned on (activated) and can’t be switched off. Mutations can also be caused by viruses, radiation, chemicals, and certain types of infections.
Most cancers start in a single cell. Over time, it grows and divides to make more cancer cells, or more mutations. Eventually, the cancer cells outgrow other healthy cells and can’t be stopped. Cancers can be any shape or size. They may form solid tumors that can be seen on the surface of the skin, or they can develop in the fluids that surround and protect the tissues inside the body, such as the blood and bone marrow. Cancers that form in the liquid part of the blood, such as leukemias and lymphomas, don’t form solid tumors but are easily detected on laboratory tests.
While a cancer diagnosis can be frightening, it is important to remember that many people with cancer live normal lives and are treated for their condition. Cancers that are caught early, when they are small in size and few in number, are often curable. Cancers that spread to other parts of the body are often treatable, too, especially if they can be removed surgically.
Researchers are investigating a number of different things that might cause cancer, and ways to prevent it. Anything that increases a person’s chance of developing cancer is called a risk factor. Factors that decrease a person’s chances of getting cancer are called protective factors. Some risk factors, like smoking, are easy to avoid, while others, such as chronic irritation of tissue, are difficult to prevent. Scientists are also studying whether there are ways to predict which people will develop cancer, and how to identify precancerous conditions in order to stop them from becoming cancer. Precancerous conditions include squamous cell carcinoma, warts, and precancerous polyps. These can be removed before they develop into full-blown cancer. For more information, see the article: What is Cancer?
Cancer is a disease that develops when cells in the body become abnormal and start growing out of control. These abnormal cells can grow into tumors, which may invade nearby tissues and spread to other parts of the body. This process is called metastasis. Cancer can be any type of cell in the body, including skin cells, bone cells, blood cells, or cells that line the digestive tract and reproductive organs. Normally, cells grow and divide to produce more cells as the body needs them. Old or damaged cells die and new cells replace them. This process is regulated by proteins that control cell growth and division, known as oncogenes and tumour suppressor genes. Cancers occur when some of these genes get changed, or mutate, and no longer control cell growth. These changes, or mutations, usually occur in parts of DNA that code for proteins. Most of the time, cancer-causing genes are turned on (activated) and can’t be switched off. Mutations can also be caused by viruses, radiation, chemicals, and certain types of infections. Most cancers start in a single cell. Over time, it grows and divides to make more cancer cells, or more mutations. Eventually, the cancer cells outgrow other healthy cells and can’t be stopped. Cancers can be any shape or size. They may form solid tumors that can be seen on the surface of the skin, or they can develop in the fluids that surround and protect the tissues inside the body, such as the blood and bone marrow. Cancers that form in the liquid part of the blood, such as leukemias and lymphomas, don’t form solid tumors but are easily detected on laboratory tests. While a cancer diagnosis can be frightening, it is important to remember that many people with cancer live normal lives and are treated for their condition. Cancers that are caught early, when they are small in size and few in number, are often curable. Cancers that spread to other parts of the body are often treatable, too, especially if they can be removed surgically. Researchers are investigating a number of different things that might cause cancer, and ways to prevent it. Anything that increases a person’s chance of developing cancer is called a risk factor. Factors that decrease a person’s chances of getting cancer are called protective factors. Some risk factors, like smoking, are easy to avoid, while others, such as chronic irritation of tissue, are difficult to prevent. Scientists are also studying whether there are ways to predict which people will develop cancer, and how to identify precancerous conditions in order to stop them from becoming cancer. Precancerous conditions include squamous cell carcinoma, warts, and precancerous polyps. These can be removed before they develop into full-blown cancer. For more information, see the article: What is Cancer?